The present invention relates generally to a differential carrier bearing cap. More specifically, the present invention relates to a differential carrier side bearing retaining cap that is universal in construction and application.
Differential axle assemblies are well known structures that are commonly used in vehicles. Differentials contain many parts to transfer the rotational force produced by the engine to the drive wheels. The typical differential is made up of a centralized carrier/housing assembly, to which axle tubes are directly or indirectly attached. The gears are housed in a portion of the differential housing called the differential carrier. Two main configurations of differential axle assemblies exist. In one configuration referred to as the spicer type, the differential carrier is an integral part of the differential housing. A second configuration, commonly called the banjo or front loader type, a separate differential carrier section is affixed to the housing. Both types of axle assemblies use the differential carrier to house the differential case. The case is equipped with anti friction side bearings on opposed ends, and is rotably secured with these bearings in machined bores made within the carrier. The bores are cylindrical in shape having one half of the cylinder machined from the carrier housing, and the corresponding other half of the bore machined from a bearing cap. Because the current caps are not standardized, the bores must be finish machined with the caps bolted in place. This machining method requires the bearing caps be oriented in exactly the same manner during assembly that they were when they were machined. This orientation is necessary to create the required bore tolerances for proper carrier side bearing alignment and preload. The process is as follows: the rough caps must be bolted in place on the carrier; the bores machined from the caps and the carrier; the caps marked for orientation, unbolted and removed from the carrier; the gears and carrier assembled; the caps reinstalled in proper orientation and bolted in place.
While the above method of machining the rough non standardized bearing caps when they are bolted in place is standard practice in the current manufacture of differentials, there are certain drawbacks associated with the machining process and the finished product. For example, the current process is inefficient in that the caps must be assembled on the differential at least twice, once for machining the bore in the rough caps and once for final assembly of the differential. Machining the bore in this manner causes the placement of the bore within the cap and the carrier to vary. This variance requires that the caps be marked for orientation after the machining process, and that subsequent assembly adhere to this orientation to assure the bores are true with respect to roundness. The bearing caps must always be installed to duplicate the orientation in which they were machined, and upon disassembly for repair or service, the orientation of the bearing caps on the carrier must be noted so that proper reassembly can occur. Failure to reassemble the caps in the proper positions can result in misalignment of the side bearings on the case and possible destruction of the differential. Furthermore, any type of failure occurring with either non standard bearing cap may necessitate the replacement of the entire differential because a standard replacement having the exact bore placement is unavailable, and if a replacement cap is used, both the cap and carrier must be remachined as a set to assure roundness of the bore.
In light of the deficiencies in prior art, the applicants"" invention is herein submitted.
The preferred embodiment of the invention discloses a differential axle assembly comprising a differential housing, a differential carrier, a differential case, bearings, bearing caps, and fasteners. A differential carrier is either integral to or attached to the differential housing. The differential carrier has a differential case therein. The differential case has a bearing disposed at each longitudinally opposed end. Each of the bearings rotably supports the differential case within the differential carrier. Each of the bearings has an outside diameter. A bearing cap retains each of the bearings in the differential carrier. The bearing cap comprises two upstanding opposed sidewall members. A web member extends therebetween. The web member has an arcuate midsection which forms a bearing recess on its inner surface. The recess corresponds with the outside diameter of the bearing. A flat retaining flange extends from either end of the web member. A retaining hole extends through each flange. The differential carrier has a machined bearing recess to receive a portion of the outside diameter of the bearing and a machined mating surface for attachment of the bearing cap. A fastener secures the bearing cap to the differential case through each retaining hole and a corresponding hole on the machined mating surface of the differential case.
The present invention provides the advantage of a differential bearing cap that is of a standard size and is formed separately from the differential carrier, so as to decrease the machining and assembly time, and to allow placement of the differential bearing cap onto the differential, indifferent to orientation.